Governor mechanism for lifting-jacks



w. E. KOMBARD. GOVERNOR MECHANISM FOR LIFTING JACKS- -APPLICAT|0N FILED AUG.2| i920. v 1,384,202 at nted Ju1ly12, 1921.

2 SHEETS-SHEET i- Ewen":

W. E. LOMBARD. GOVERNOR MECHANISM FOR LIFTING JACKS- APPLICATION FILED Aue.2. 1920.

1 384,2(92, V Patented July 112, 1921.

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WALTER- nfnontnenn, or ARLINGTON, nassacnusnrrs, ASSIGNOR TO A. 0. NORTON, Inc, or BOSTON, MesSaonUSnrrS, A conPonerroN or MAINE.

eovnnNon MECHANISM non LIFTING-JACKS.

Specification of Letters Patent.

Patented July 12, 19231.

Application filed August 2, 1920. Serial No. @0524.

To all whom it may concern Be it known that I, lVAL'rnn E. LOMBARD, a citizen of the United Stat-es of America, and a resident of Arlington, in the county of Middlesex and State of Massachusetts, have invented certain'new and useful Improvements in Governor Mechanism for Lifting- Jacks, of which the following is a specification.

This invention relates to governor mechanism for lifting jacks and particularly that class of screw jacks which are adapted to lower under the weight of the load, the ob ject of the invention being to provide a simple and effective means for controlling the speed of the lowering member and insuring its rotation at a uniform speed.

One of the objects of the invention is to locate the one-way driving connection be tween the worm shaft and the main operating shaft at a point where it is accessible when it is desired to repair the same.

The invention consists in loosely mounting on a driving shaft the worm gear coacting with ;the governor actuating worm and securing to said driving shaft a disk carrying pawls adapted to coact with a rathet revoluble with said worm gear whereby said worm gear will be driven in one direction only and this'during the lowering of the load.

The invention further consists in certain novel features of construct-ion and arrange ment of parts which will be understood readily by reference to the description of the drawings and to the claims to be hereinafter given. v

For the purpose of illustrating the invention, one preferred form thereof is illustrated in the drawings, this form having been found to give satisfactory and reliable results although it is to be understood that the various instrumentalities of whichthe invention consists can be variously arranged and organized and the invention is not limited to the precise arrangement and organization of these instrumentalit'ies' as herein shown and described, except as required by the scope of the'appended claims.

Of the drawings:

Figure 1 represents a vertical section of a lifting jack embodying the principles of the present invention.

Fig. 2 represents a horizontal section on line 2, 2, on Fig. 1.

I Fig. 8 represents an enlarged vertical section of the one-way driving connection adapted to rotate the worm gear in one direction only.

F 1g. & represents a section on line Fi 1,} w 1 1g. 0 iepiesems a veitlcal SQCLlOll showmg the overnor mechanism in elevation.

rig. o represents a vertical section showing the manually controlled brake mechanism, and

F 1g. '4' represents an elevation of the acturemoving the brake arms from the ator for brake wheel.

Similar characters throughout ings.

in the drawings, 10 represents a suitable base supporting a stationary standard 11 over the outer periphery of which is fitted a movable sleeve 12, to the upper end of which is threaded a cap 13.

In the upper end of the standard 11 is mounted a nut lei to which is threaded a lifting screw 15 having splined to its upper re: duccd end a bevel gear 16 with which meshes a bevel gear 17 formed upon or Secured to a revoluble shaft or spindle 18, the outer end of which is provided with a suitable operating mechanism 19 of any well-known construction.

' Between the upper face of the bevel gear 16 and the inner face of the cap 13 are two annular plates 20, 21, between which are interposed a plurality of antifriction mem bers 22. r

The movable member 12 is provided on one side with a flanged projection 21 having a removable plate 25 secured thereto by bolts 25*. I 3

The plate 25' is provided with a bearing 26 for the spindle or shaft 18 and secured to the shaft is a gear 2? revoluble with said shaft in either direction.

indicate like parts the several figures of the draw- Beneath the gear wheel 27 is a revoluble' periphery of which coracts two brake members 43 pivoted at 44 to the bracket 40.

The lower end of each brake member 43 is provided with a recess 45 in which is positioned one end of a helical spring 46 the opposite ends of i in the recesses 47 and 48 in the removable plate 25 and bracket 40'.

Between the lower adjacent ends of the brake members 43 is positioned a flat sided projection 49 formed upon the actuating lever 50.

A portion of the fiat sided projection 49 is cylindrical and positioned in a cylindrical hole in the flange of the removable plate 25.

The springs 46 normally retain the brake members in contact with the periphery of the disk 42 and prevent its rotation until the actuating lever 50 is moved to cause said flat sided projection 49 to, separate said brake members 43 and remove them from contact with the disk 42.

The worm 31 is provided at its opposite end witha reduced end 51 to which is secured a disk 52 having mounted thereon two slidable members 54, the outer ends of which have broad bearing flanges 55, the outer faces of which are curved to fit the cylindrical wall 56 of a chamber formed in the bracket 40.

The inner face 57 of the flange isflat and forms a bearing surface for the cam projection 58 on the lever 60 pivoted at 61 and provided on its free end with the weight 62.

This governor is the same and operates in the same manner as that shown and described in U. S. Patent No.- 1,324,346 issued to Frank L. Gormley, Dec. 9, 1919, to which reference may be made for details of construction.

The removable. cover plate 25 is provided with semi-cylindrical recesses 67, 68 into which portions of the governor and brake mechanism project.

When the cover plate 25 is removed from the flanged projection 24 all of the devices for controlling the lowering of the movable member 12 areremoved therewith.

The shaft of worm 31 is provided with an anti-friction device 72 adapted to take care of the end thrust of the worm 31-during the lowering of the jack.

The driving shaft 28 has keyed or otherwise secured thereto, a disk 7 3' having projecting lugs 7 4 to the ends of which is secured a ring 75 by means of screws 76.

Tnterposed between the ring 75 and the disk 7 3 are a plurality of pawls 7 7 each pivoted at 78 and having the outer ends thereof pressed inwardly by helical springs 79 into contact with the teeth of the ratchet 80 secured to the hub of the worm gear 30.

The reducedouter end 81 of the driving shaft 28 has a bearing in a cylindrical socket said springs being disposed 82 formed in a removable member 83 threaded to the cover 25 as indicated in Fig, 1 of the drawin s. 7

This plate or member 83 is cylindrical and of a diameter somewhat greater than the diameter of the worm gear 30 so that when the member 83 is removed fromthe cover plate 25 the disk 7 3, worm gear 30, and shaft 28 may be readily removed from the casing of the jack without disturbing other parts thereof,

This is of great convenience as usually there is more trouble with the one-way driw ing connection than with any other part.

of the jack.

This provides a means whereby this connection may be removed at any time for repair. Y I

In the operation of the device, the gear 27 is rotatable with the operating shaft 18 in either direction and consequently the shaft 28 rotates in either direction during the'rais- 7 ing: and lowering of the load.

hen the load is being raised however the pawls 77 ride over the teeth ofthe ratchet 80 and consequently no motion is imparted to the worm gear 30which is loosely mounted upon theshaft prevented from turning thread of the worm 31-.

28 and normally is by means of the lVhen the load is being lowered, however.

under its own weight the pawls 77 will engage the teeth of the ratchet 80. and rotate the worm gear 30 which in turn will cause the rotation of the worm on whichethe governor mechanism and brake wheel are both mounted.

Obviously the pitch of the thread of the worm 31 must be of such inclination as will permit said worm to be revolved about its axis when the worm gear 30 is rotated about the axis of the driving shaft 28 during the lowering operation.

Should the worm 31 start to rotate at an excessive speed under the weight of the load, th members 60 will be thrown outwardly by centrifugal force causing the shoes 55 to be moved into frictional engagement with the cylindrical wall 56 of the governor casing. 1

This will cause a reduction in the speed of rotation of the worm shaft and results in" the load being lowered at a comparatively uniform speed. s

Shouldit be desired to stop the lowering at any particular point, pressure onthe' actuating member 50 is removed and the springs 46 will return the brake arms 43 into contact with the brake wheel 42 and immediately prevent further lowering. r These brake arms 43 coacting with the brake wheel 42 are suflicient to retain the load in elevated position until it is desired to lower the same. i

It is believed that from the foregoing description, the operation and many advantages of the present invention Will be readily understood.

Having thus described my invention, I claiml. The combination with a lifting jack having a driving shaft adapted to be rotated in either direction; a disk revoluble therewith; a worm gear loosely mounted on said drivin shaft; a ratchet revoluble with said gear; pawls on said disk coacting with said ratchet; a worm adapted to be driven inone direction only by said worm gear; and a governor actuated by said worm.

2. The combination with a lifting jack having a driving shaft adapted to be rotated in either direction; a worm gear loosely mounted on said driving shaft; a worm meshing with said gear and adapted to be driven thereby; a governor actuated by said worm; and a one-way driving connection between said driving shaft and said worm gear.

The combination with a lifting jack havin a driving shaft adapted to be rotated in either direction; a worm gear loosely mounted on said driving shaft; a worm meshing with said gear and adapted to be driven thereby; a governor actuated by said worm; a one-way driving connection between said driving shaft and said worm gear; and a removable bearing for the outer end of said driving shaft.

'1 The combination with a lifting acl: having a driving shaft adapted to be rotated in either direction; a worm gear loosely mounted on said driving shaft; a worm meshing with said gear and adapted to be driven thereby; a governor actuated by said worm; a one-way driving connection between said driving shaftand said worm gear; and a removable member secured to the jack casing and provided with a bearing for the outer end of the driving shaft.

5. The combination with a lifting jack having an operating shaft and a driving shaft; a pinion secured to said driving shaft; a gear secured to and revoluble in either direction with the operating shaft and meshing with said pinion; a worm gear loosely mounted on said driving shaft; a worm meshing with said worm gear; a governor actuated by said worm; and a oneway driving connection between said driving shaft and said worm gear.

6. The combination with a lifting jack having an operating shaft and a driving shaft; a pinion secured to said driving shaft; a gear secured to and revoluble in either direction with the operating shaft and meshing with said pinion; a worm gear loosely mounted on said driving shaft; a worm meshing with said worm gear; a governor actuated by said worm; a ratchet secured to said worm gear; and pawls carried by said driving shaft and coacting with said ratchet whereby rotation is imparted to said worm gear in one direction only.

7. The combination with a lifting jack having a revoluble operating shaft; a revoluble pawl-carrying member rotatable in either direction by said operating shaft; a worm gear alined with said pawl-carrying member; a ratchet carried thereby coacting with said pawls; a worm meshing with said worm gear; and a governor actuated by said worm.

8. The combination with a lifting jack having a revoluble operating shaft; a revoluble pawl-carrying member rotatable in either direction by said operating shaft; a worm gear alined with said pawl-carrying member; a ratchet carried thereby coacting with said pawls; a worm meshing with said worm gear; a governor actuated by said worm; and a manually controlled brake wheel rotated in one direction only by said worm.

9. The combination with a lifting jack having a revoluble operating shaft; a revoluble pawl-carrying member rotatable in either direction by said operating shaft; a worm gear alined with said pawl-carrying member; a ratchet carried thereby coacting with said pawls; a worm meshing with said worm gear; and a manually controlled brake wheel rotated in one direction only by said worm.

WALTER E. LOMBARD. 

